1. Field of the Invention
The present invention relates to wireless communications, and more particularly, to a method and apparatus for performing measurements logging in a wireless communication system.
2. Related Art
3rd generation partnership project (3GPP) long term evolution (LTE) is an improved version of a universal mobile telecommunication system (UMTS) and is introduced as the 3GPP release 8. The 3GPP LTE uses orthogonal frequency division multiple access (OFDMA) in a downlink, and uses single carrier-frequency division multiple access (SC-FDMA) in an uplink. The 3GPP LTE employs multiple input multiple output (MIMO) having up to four antennas. In recent years, there is an ongoing discussion on 3GPP LTE-advanced (LTE-A) that is an evolution of the 3GPP LTE.
Minimization of driving tests (MDT) is a test performed by service providers for coverage optimization by using a user equipment (UE) instead of using an automobile. A coverage varies depending on a location of a base station (BS), deployment of buildings nearby, a user's usage environment, etc. Therefore, it is required for the service providers to periodically perform the driving test, and a lot of costs and resources are consumed. The MDT is used when the service provider measures the coverage by using the UE.
In the conventional technique, an MDT configuration transmitted to the UE in one cell is not reported to a neighbor cell. Therefore, if the UE moves to the neighbor cell, a new MDT configuration is possibly received from the neighbor cell. Since the UE can apply only one MDT configuration at one time, one of the MDT configuration of the old cell and the new MDT configuration is discarded.
A specific MDT configuration to be applied to the UE and a way of handling an MDT measurement result based on the old MDT configuration have not been provided for a case where a plurality of MDT configurations exist